Bases used as condensation reaction catalysts such as 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU); 1,5-Diazabicyclo[4.3.0]non-5-ene; 1,4-Diazabicyclo[2.2.2]octane (DABCO); and others suffer from the drawback of inhibition of catalysis when a filler is added to a composition containing such catalyst. Metallic condensation reaction catalysts (such as acetyl acetonates of aluminum or zinc) suffer from the drawback of causing scission of aromatic groups from siloxane resins, particularly resin-linear compounds. There is an industry need for catalysts that can deliver controlled cure of siloxane compounds, including resin-linear compounds, via condensation reaction in the presence of untreated fillers, such as phosphors.